sciencegeekgirl » Pretty traces of light!

Welcome to the first post at the new blog location! Now that my webhome is established I can start posting more regularly. Geek on!

Sebastien Martin of the Exploratorium has been working with what you can do with light traces — basically, tracing out the motion of something through space using light (say, by attaching an LED to the object and taking a time-lapse picture of it) for a while. He did some stuff with the science of baseball showing the path of a baseball through space, and has also posted some great pix on Flickr. Here is what he says about how to make these traces:

All the pictures were taken with a regular digital camera set to an exposure time of 0.5 to 3 seconds. The lines you see were created by LED lights attached to moving objects.

You can use any small light source to make the trace of a moving object visible (bicycle light, flash light, key light). Just attach the light to the object, and make sure the room is completely dark. Then take a long exposure picture of the moving light using your Digi Cam.

It’s also fun to go further and analyze the speed of the object! To do that, use a fast blinking LED light (such as the Inova pulsed LEDs you can buy at Target Stores for $7). The distance between the dots is a measure of speed.